Research on Structural Damage Diagnosis Based on Strain Modal

2013 ◽  
Vol 438-439 ◽  
pp. 739-742
Author(s):  
Yi Na Zhang ◽  
Lei Cao
Keyword(s):  
Damage Detection ◽  
Cantilever Beam ◽  
Theoretical Basis ◽  
Structural Damage ◽  
Damage Identification ◽  
Damage Diagnosis ◽  
Strain Mode ◽  
Engineering Structure ◽  
Displacement Mode ◽  
Analysis Theory

The damage diagnosis theory and method of engineering structure is one of the hot issues concerned by the engineering circles at present. Based on the strain modal analysis theory, it expounds the connection among displacement mode, strain mode and curvature mode, with a heavy rubber as the material to make a cantilever beam, and establishing the different damage conditions of the cantilever beam, studying about dynamic structural damage identification under the incentive, which provides the theoretical basis and technical support for the research on damage detection of large engineering structure.

The Damage Identification of Multilayer Frame Structure Containing Sheet Crack by Wavelet Analysis

2012 ◽  
Vol 193-194 ◽  
pp. 1001-1004
Author(s):  
De Qing Guan ◽  
Liang Liu
Keyword(s):  
Wavelet Analysis ◽  
Structural Damage ◽  
Damage Identification ◽  
Frame Structure ◽  
The Finite Element Method ◽  
Damage Diagnosis ◽  
Structure Damage ◽  
Analysis Theory ◽  
Modulus Maxima ◽  
Calculation Analysis

In this paper, the multilayer frame structure containing sheet crack was researched. Based on wavelet analysis theory, the finite element method was applied to analyze the dynamic characteristics of structural damage. Established a method about the identification of containing sheet crack frame structure by modulus maxima of wavelet coefficients to determine the location of the crack, it verifies the validity of the method through calculation analysis of damage identification to a two layers of a cross frame structure containing sheet crack. The conclusions of this paper can be used for frame structure damage diagnosis application reference.

Sparse damage detection via the elastic net method using modal data

2021 ◽  
pp. 147592172110219
Author(s):  
Rongrong Hou ◽  
Xiaoyou Wang ◽  
Yong Xia
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Measurement Data ◽  
Elastic Net ◽  
Sensitivity Matrix ◽  
Regularization Technique ◽  
Modal Data ◽  
Regularization Techniques ◽  
Net Method

The l1 regularization technique has been developed for damage detection by utilizing the sparsity feature of structural damage. However, the sensitivity matrix in the damage identification exhibits a strong correlation structure, which does not suffice the independency criteria of the l1 regularization technique. This study employs the elastic net method to solve the problem by combining the l1 and l2 regularization techniques. Moreover, the proposed method enables the grouped structural damage being identified simultaneously, whereas the l1 regularization cannot. A numerical cantilever beam and an experimental three-story frame are utilized to demonstrate the effectiveness of the proposed method. The results showed that the proposed method is able to accurately locate and quantify the single and multiple damages, even when the number of measurement data is much less than the number of elements. In particular, the present elastic net technique can detect the grouped damaged elements accurately, whilst the l1 regularization method cannot.

Structural Damage Assessment Using Output-Only Measurement: Localization and Quantification

2013 ◽  
Author(s):  
Chin-Hsiung Loh ◽  
Min-Hsuan Tseng ◽  
Shu-Hsien Chao
Keyword(s):  
Damage Detection ◽  
Damage Assessment ◽  
Structural Damage ◽  
Damage Identification ◽  
Model Updating ◽  
Null Space ◽  
Singular Spectrum Analysis ◽  
Damage Index ◽  
Computation Efficiency ◽  
Output Only

One of the important issues to conduct the damage detection of a structure using vibration-based damage detection (VBDD) is not only to detect the damage but also to locate and quantify the damage. In this paper a systematic way of damage assessment, including identification of damage location and damage quantification, is proposed by using output-only measurement. Four level of damage identification algorithms are proposed. First, to identify the damage occurrence, null-space and subspace damage index are used. The eigenvalue difference ratio is also discussed for detecting the damage. Second, to locate the damage, the change of mode shape slope ratio and the prediction error from response using singular spectrum analysis are used. Finally, to quantify the damage the RSSI-COV algorithm is used to identify the change of dynamic characteristics together with the model updating technique, the loss of stiffness can be identified. Experimental data collected from the bridge foundation scouring in hydraulic lab was used to demonstrate the applicability of the proposed methods. The computation efficiency of each method is also discussed so as to accommodate the online damage detection.

Review on Damage Identification and Diagnosis Research of Civil Engineering Structure

2014 ◽  
Vol 1006-1007 ◽  
pp. 34-37 ◽  
Author(s):  
Hong Ni ◽  
Ming Hui Li ◽  
Xi Zuo
Keyword(s):  
Structural Damage ◽  
Civil Engineering ◽  
Damage Identification ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Civil Engineering Structure ◽  
Structure Damage ◽  
Development Direction ◽  
Structural Damage Identification ◽  
Civil Engineering Structures

This paper first describes the importance of structural damage identification and diagnosis in civil engineering, and introduces domestic and foreign status of damage identification and diagnosis methods, and on the basis of this, it also introduces all kinds of methods for damage identification and diagnosis of civil engineering structures, and finally puts forward the development direction of civil engineering structure damage identification and diagnosis.

scholarly journals Structural Damage Identification Based on the Minimum System Realization and Sensitivity Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
W. R. Li ◽  
Y. F. Du ◽  
S. Y. Tang ◽  
L. J. Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Structural Information ◽  
Structural Response ◽  
Frame Structure ◽  
Structural Damage Detection ◽  
System Realization ◽  
Minimum System

On the basis of the thought that the minimum system realization plays the role as a coagulator of structural information and contains abundant information on the structure, this paper proposes a new method, which combines minimum system realization and sensitivity analysis, for structural damage detection. The structural damage detection procedure consists of three steps: (1) identifying the minimum system realization matrixes A, B, and R using the structural response data; (2) defining the mode vector, which is based on minimum system realization matrix, by introducing the concept of the measurement; (3) identifying the location and severity of the damage step by step by continuously rotating the mode vector. The proposed method was verified through a five-floor frame model. As demonstrated by numerical simulation, the proposed method based on the combination of the minimum realization system and sensitivity analysis is effective for the damage detection of frame structure. This method not only can detect the damage and quantify the damage severity, but also is not sensitive to the noise.

Structural Damage Detection Depending on Curvature Matrix of Change in Flexibility

2011 ◽  
Vol 255-260 ◽  
pp. 389-393
Author(s):  
Yong Mei Li ◽  
Bin Zhou ◽  
Xi Yuan Zhou ◽  
Guo Fu Sun ◽  
Bo Yan Yang
Keyword(s):  
Numerical Simulation ◽  
Damage Detection ◽  
Cantilever Beam ◽  
Lower Order ◽  
Structural Damage ◽  
Structural Damage Detection ◽  
Principal Diagonal ◽  
Simply Supported ◽  
Damage Location ◽  
Difference Calculation

Flexibility is more sensitive to structural damage than frequency or mode. Curvature matrix of change in flexibility is presented as a new index of nondestructive damage detection, which is derived from change in structural flexibilities calculated from before damaging and after damaging by means of difference calculation twice, firstly to columns, and then to rows. Therefore a new indicator called as δ Flexibility Curvature Matrix Diagonal (δFCMD) is constructed from the principal diagonal elements based on curvature matrix of change in flexibility. The numerical simulation examples indicate that the damage location and severity in structures, with single damage, multiple ones, slight ones and ones at the supports, can be detected efficiently for a cantilever beam, a fixed supported beam, a simply supported beams and so on by the indicator of δFCMD depending on only a few of lower order modes.

A One Stage Damage Detection Technique Using Spectral Density Analysis and Parallel Genetic Algorithms

2013 ◽  
Vol 558 ◽  
pp. 1-11 ◽  
Author(s):  
Maryam Varmazyar ◽  
Nicholas Haritos ◽  
Michael Kirley ◽  
Tim Peterson
Keyword(s):  
Spectral Density ◽  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Search Space ◽  
Model Parameters ◽  
Multiple Time ◽  
One Stage ◽  
Periodic Monitoring ◽  
Output Only

This paper describes a new global damage identification framework for the continuous/periodic monitoring of civil structures. In order to localize and estimate the severity of damage regions, a one-stage model-based Bayesian probabilistic damage detection approach is proposed. This method, which is based on the response power spectral density of the structure, enjoys the advantage of broadband frequency information and can be implemented on input-output as well as output-only damage identification studies. A parallel genetic algorithm is subsequently used to evolve the optimal model parameters introduced for different damage conditions. Given the complex search space and the need to perform multiple time-consuming objective function evaluations, a parallel meta-heuristic provides a robust optimization tool in this domain. It is shown that this approach is capable of detecting structural damage in both noisy and noise-free environments.

Study on Damage Location of Spatial Structures Based on Wavelet Analysis of Model Strain Energy

2013 ◽  
Vol 639-640 ◽  
pp. 1033-1037
Author(s):  
Yong Mei Li ◽  
Bing Zhou ◽  
Guo Fu Sun ◽  
Bo Yan Yang
Keyword(s):  
Wavelet Analysis ◽  
Damage Detection ◽  
Structural Damage ◽  
Strain Energy ◽  
Damage Identification ◽  
Damage Index ◽  
Structural Damage Detection ◽  
Modal Strain Energy ◽  
Wavelet Method ◽  
Long Span

The research to identify and locate the damage to the engineering structure mainly aimed at some simple structure forms before, such as beam and framework. Damage shows changes of local characteristics of the signal, while wavelet analysis can reflect local damage traits of the signal in time domain and frequency domain. For confirming the validity and applicability of structural damage identification methods, wavelet analysis is used to spatial structural damage detection. The wavelet analysis technique provides new ideas and methods of spatial steel structural damage detection. Based on the theory of wavelet singularity detection，with the injury signal of modal strain energy as structural damage index，the mixing of the modal strain energy and wavelet method to identify and locate the damage to the spatial structure is considered. The multiplicity of the bars and nodes can be taken into account, and take the destructive and nondestructive modal strain energy of Kiewitt-type reticulated shell with 40m span as an example of numerical simulation，the original damage signal and the damage signal after wavelet transformation is compared. The location of the declining stiffness identified by the maximum of wavelet coefficients，analyzed as signal by db1 wavelet，and calculate the graph relation between coefficients of the wavelets and the damage to the structure by discrete or continuous wavelet transform, and also check the accuracy degree of this method with every damage case. Finally，the conclusion is drawn that the modal strain energy and wavelet method to identify and locate the damage to the long span reticulated shell is practical, effective and accurate, that the present method as a reliable and practical way can be adopted to detect the single and several locations of damage in structures.

scholarly journals Multi-class Damage Detection and Localization Using Long Short-Term Memory (LSTM) Networks

2021 ◽  
Author(s):  
Sandeep Sony
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Short Term Memory ◽  
Damage Identification ◽  
Binary Classification ◽  
Short Term ◽  
Damage Classification ◽  
Term Memory ◽  
Long Short Term Memory ◽  
Lstm Network

In this paper, a novel method is proposed for detecting and localizing structural damage by classifying acceleration responses of a structure using a long short-term memory (LSTM) network. Windows of samples are extracted from acceleration responses in a novel data pre-processing pipeline, and an LSTM network is developed to classify the signals into multiple classes. A predicted classification of a signal by the LSTM network into one of the damage levels indicates a damage detection. Furthermore, multiple signals obtained from the vibration sensors placed on a structure are provided as input to the LSTM model, and the resulting predicted class probabilities are used to identify the locations with high probability of damage. The proposed method is validated on the experimental setup of the Qatar University Grandstand Simulator (QUGS) for binary classification, as well as, full-scale study of the Z24 bridge benchmark data for multi-class damage classification. Experiments show that the proposed LSTM-based method performs on par with 1D convolutional neural networks (1D CNN) on the QUGS dataset, and outperforms the 1D CNN on the Z24 dataset. The novelty of this study lies in the use of recurrent neural network based LSTM for vibration data for multi-class damage identification and localization.

Structural Damage Identification With Performance-Based Uncertainty Quantification

2010 ◽  
Author(s):  
Jiann-Shiun Lew
Keyword(s):  
Damage Detection ◽  
Uncertainty Quantification ◽  
Structural Damage ◽  
Damage Identification ◽  
Singular Value ◽  
False Identification ◽  
Control Techniques ◽  
Performance Metric ◽  
Parameter Variations ◽  
Value Decomposition

This paper presents an investigation of damage detection of a structure with significant uncertainty. The proposed approach integrates the performance-based uncertainty quantification and feedback control techniques for damage identification. A singular value decomposition (SVD) technique is used to decompose parameter variations into principal components that are weighted with the sensitivity of the performance metric for damage detection. This SVD technique can be used to differentiate between dominant uncertainties and minor uncertainties corresponding to damage identification. To improve the performance of damage identification under uncertainty, a feedback controller is incorporated into the structure to reduce the effect of the quantified uncertainty. The probability framework, based on Monte Carlo simulation, is used to predict the false identification of damage. Examples based on the structural dynamics challenge problem issued by Sandia National Laboratories are used to demonstrate the proposed techniques.

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